Electric incandescent lamp



March 31, 1953 L. F. KRAMEL 2,533,543

ELECTRIC INCANDESCENT LAMP Filed Jan. 25, 1951 Invervtov: Leonavd F KT'ameL,

Patented Mar. 31, 1953 ELECTRIC INCANDESCENT LAMP Leonard-F; Kramel; Lyndhurst; Ohio; assignor'to General Electric Company, a corporation of.

New York;

Application Jamaal-$125, 1951; swarm. 207,777"

My; invention "relates in" general to" electric incandescent lamps and sirnilardevices; and'more' particularlyrto afilament 'inlead' and" supporting struoture'for'lamps of the type employing an envelope. comprising two pressed glass sections fusion-sealed together'at their'rims;

j Electric incandescent lamps of the-'so-called (sealed beam type are in'general use at'pr'esent for many purposes; such as for automotive head'- lights and airplane landinglights; for example: Such lamps generally comprise an envelope or bulb composed of pressed glass'refiector and'cover sections fusion-sealed together at their rims. The lead-inconductors for the lamp filamentare generally sealed through thereil'ector sectionby means ofsmall'metal' capsor thimble lilie fez-=- rules. which coveropenings in the-wall of the reflector sectionand are fusion-sealed'at their tliih'.rim edgesto the glassborderingthe said Openings. Secured to the inner sides of the ferrules, .as by solderingfor instance, are the inner lead -in conductors which are connected'to and.

support. the. lamp. filament accurately. in place, while at. their outersides the said. ferrules are provided with terminals, binding screws, or the like, for connecting. the current supply. wires thereto; The. sealing of the: lead-in-conductors to. the glass envelope is thus eifectedatth'e. rims or edges of. the imetal ferrules. Usually, an. exhaust tube is also providedas .an integral 'partlof the glassreflector. section for evacuation of'the lamp,v envelope.

. Iniorderto assurean eiiectivesealb'etween the glass and'the. metalferrules in suchv type lamps,- it" is necessary that the ferrules be made ofa material having a. coeflicient of expansion. more orless matching. that of theglass to. which .it is sealed andlthatit have the ability toreadily-wetf andladhere to the glass. For this reason, there.- fore, it hasbeen heretofore necessary to make the metal-ferrules of a special relatively expensivechrome-iron alloy. Moreover, the insertion and-sealing of theseferrules into theglass refiector section is performed. separately fromthe sealing together of the reflector and cover glass. sections and thusconstitutes an additional operation/adding, to the-manufacturingcost of the lamp.

Itis anobjectof my invention, therefore, to provide an electric incandescent lamporsimilar deviceofthe above-mentioned general type which is. of. simple and relatively inexpensive construe-- tion and which is easy to fabricate.

' Another object of my invention is to provide an.electricincandescent lamp or similar device of. theabovementioned general character but employing instead conventional type lamp lead-in conductors orwires, and the sealing-in of which conductors through the wall of the lampenvelope is. combined 1 and performed. simultaneously with theisealingtogether of the separateglassparts orwhicn the envelope formedI' Accordingto' the invention, the lead-in conductorsaresealed'through the fused seal join-- ing the reflector and cover glass sectionsof the lampenvelope and are, in addition, provided with support brace' portions or extensions which project into andengage the walls of indentations in the'envelope wall to thereby anchor the inner end portions of the conductors and fixedly position electricincandescent lamp comprisin my 'inventionyFigs. 2 and 3 are fragmentary perspective views of two different modified forms of mount constructions'for the lamp or my invention; and Fig.14is an exploded fragmentary sectional view showing thetwo glass parts of the lamp envelope and'a lea'd-in' conductorin position prior to the formation of the fused seal therebetween.

Referring to the drawing, the lamp there shown comprises a bulb or envelope! consisting of a preformed concave glass reflector section 2 and a preformed cover glass section 3 fusion-sealed together at their rims to form the envelope. The two envelope sections 2 and 3 are made of pressedglass and are provided at their rims with outwardl'yextendin flanges 4 and 5, respectively, having upstanding sealing ridges 8' and I (Fig. 4) which are'fusion-sealed together. The-inner surface 8" of thereflector section 2 is shaped as an optical reflector/surface of revolution, such as a paraboloid forinstance, and it is provided with a-suitable' reflective metallic coating 9, such as aluminum orsilver, to constitute it a reflecting surface. Anexhaust tubulation i0 is provided at the apex of the'refiector section 2 for evacuation and, if desired; gas filling the lamp envelope 1, after which operations the said tubulation is tipped-off as shown at l l to thereby hermetically seal the envelope.

Sealed Within the lamp envelope I is a mount structure [2 comprising a pair of relatively rigid lead-in conductors 'or wires l3, l3 connected'ad-' jacent their inner ends to an electrical energy translation element, or a concentrated light source or filament M, such as a coiled or coiledcoil wire of tungsten or 'other'suitable'refractory metal; In the particular case shown, the-filament [4' is in the'form of a linear coil extending transversely of the axis X of the reflecting surface 9through'1the focus F thereof.

In accordance with the invention, the lead-in conductors or wires [3, 13 are sealed through the fused seal joining the reflector and cover glass sections 2, 3 together at their rims. For this purpose, the conductors' or wires I3, 13 are preferably of the conventional multi-section type comprising'inner'and outer leads l5 and [6, respectively, joined end-to-end by and butt-welded to an intermediate seal lead I! made of a suitable metal which has a coefficient of expansion more or less matching that of the particular glass of which the reflector and cover glass sections 2, 3 are formed and which will readily wet" and adhere to such glass. For a hard heat-resistant glass of the well-known borosilicate type, the seal lead portions II of the conductors I3 may be made, for instance, of tungsten or molybdenum, or of an iron-nickel-cobalt alloy, or a nickel or chrome-iron alloy. The inner and outer lead portions I5 and I6 are preferably made of a suitable less expensive material, such as iron or nickel-plated iron for instance. The seal and inner lead portions I7 and I5, respectively, of the conductors I3 are, in addition, made of a sufficiently large diameter (for example, to 80 mils or thereabouts) to be relatively rigid and thus hold and support the filament 14 in position at all times in the envelope I.

From the points where they are sealed through the fused seal joining the envelope sections 2, 3. the lead-in conductors I3, I3 extend more or less radially inward of the envelope I, i. e., toward the axis X of the reflector section 2, and are suitably connected to the opposite ends of the filament It, as by welding or clamping, for instance. In the case of a single filament lam such as illustrated, the two conductors I3, I3 therefor are preferably sealed through the fused seal between the envelope sections 2, 3 at diametrically opposite points thereof, and they extend inwardly therefrom preferably in a common radial plane approximately including the reflector axis X.

To brace or anchor the inner ends of the leadin conductors I3, I3 in place against movement, and to also accurately locate and fix the filament I4 in predetermined position relative to the reflecting surface 9, the lead-in conductors 13 are, in accordance with the invention, provided at their inner ends with brace means or support brace portions I8 which extend into and bear against the walls of locating indentations or dimples l9 formed in the inner surface 8 of the refiectorsection 2. In the particular form of the invention shown in Fig. l, the support brace porconductor extensions I8 extending into and bearing against the walls of the locating indentations or dimples I9 in the reflector section 2. To assist in holding the mount in place during the sealing operation and permit the sealing "ridges 6, I to abut one another, the sealing facesof the sealing ridges B, I are preferably provided, respectively,

- with matching cross grooves 23 and 24 (Fig. 4)

. the case of a single filament lamp such as illustions I8 are in the form of inner extensions of the lead-in conductors I3, I3, the latter being suitably bent to provide such support brace portions. As shown, the support braces I8 extend in the same general direction as the reflector axis X and, in the case of a single filament lamp such as illustrated, they are also preferably located approximately in the same common plane with the inner lead portions l5 of the conductors 13. If desired, the mount I2 may be rigidified, and formed as a unitary structure to facilitate handling thereof as a unit during fabrication of the lamp, by means of an insulative bridge or tie member 20 fastened across the brace wires I8 and comprising either a glass bead or button embedding the brace wires or, as shown, a short length of glass rod 2| or other suitable insulative material carrying at each end a pair of support wires 22 which are welded or otherwise fastened to the brace wires l8.

In fabricating the lamp according to the invention, the two glass sections 2, 3 are assembled and held in proper sealing relation, with their sealing ridges 6, 1 closely adjacent or abutting one another and the mount I2 positioned and held in place with the seal portions ll of the lead-in conductors [3 extending between the sealing ridges 6, I and the ends of the brace wires or trated, the conductor-locating grooves 23, 24 in the sealing ridges 6, I are preferably located in approximately the same radial plane of the reflector section 2 as the brace wire anchoring indentations I9 in the reflector section.

In the modification of the invention shown in Fig. 2, the filament I5 is clamped to the lead-in conductors l3 instead of being welded thereto as shown in Fig. 1. For this purpose the lead-in conductors [3 are formed with a double bend to provide hooks 25 within which the ends of the filament I4 are clamped.

The modification shown in Fig. 3 diifers from the previous forms of the invention in that the support brace means for the inner ends of the lead-in conductors 26 are formed by separate wire members 27 which are suitably secured to the conductors, as by welding for instance. In the particular construction shown in Fig. 3, the brace wires 21 themselves, rather than the conductors 2B, are connected to the ends of the filament I4, they being provided for such purpose with hooks 28 within which the filament ends are clamped. It will be understood, however, that if desired the filament l4 could be connected directly to the lead-in conductors 26 instead of to the brace wires 21, and that the connections between the filament I4 and the brace wires 21 or conductors 26 could be effected by means other than the clamping connection illustrated, e. g., by welding.

While the invention has been illustrated only in connection with a single filament lamp, it will be obvious that it is applicable as well to a multifilament lamp. In such case, the individual leadin conductors are preferably each provided with individual support brace portions or extensions I8 or 21 which extend into and bear against the walls of corresponding locating indentations or dimples I9 in the inner surface 8 of the reflector section 2.

It will be evident that the engagement of the support brace portions I8 of the mount l2 with the indentations IS in the reflector section 2 not only serves to anchor and hold in place the inner ends of the lead-in conductors, but also to locate and fix the filament M in predetermined position relative to the reflecting surface 9 during the sealing-in of the mount I2 as well as during the subsequent use of the lamp. It is also apparent that the lamp construction of the invention is relatively simple and in expensive, and that by sealing the lead-in conductors of the lamp in the fused seal joining the reflector and cover glass sections the sealing-in of such conductors in the lamp envelope may be performed concomitantly with the sealing together of the envelope sections 2, 3, thus eliminating the need for separate sealing operations such as are required in the manufacture of conventional type sealed beam lamps as described previously. The manufacture of the lamp according to the invention is thereby considerably simplified.

Although preferred embodiments of my invention have been disclosed, it will be understood that the invention is not to be limited to the speciflc construction and arrang merit of parts shown, but that they may be widely modified within the spirit and scope of my invention as defined by the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

i. an electric lamp or similar device coni= prising a sealed envelope including glass reflector section and a glass cover section joined to gether at their rims by a fused seal, an elecrical energy translation element within aid onvelope, and a pair of relatively rigid lead-in con ductors seaie'l through the said fused seal and connected to the said translation element, said reflector section having its inner surface formed with a locating indentation therein, and said lead-in conductors being provided adjacent their inner ends with relatively rigid brace means extending into and bearing against the wall of said indentation to thereby anchor and position the said inner ends of the conductors in place within the envelope and accurately locate and maintain the said translation element in predetermined optical position relative to the reflecting surface of the reflector section.

2. An electric lamp or similar device comprising a sealed envelope including a glass reflector section and a glass cover section joined together at their rims by a fused seal, an electrical energy translation element within said envelope, and a pair of relatively rigid lead-in conductors sealed through the said fused seal and connected to the said translation element, said reflector section having its inner surface formed with a pair of locating indentations therein, and said lead-in conductors being provided adjacent their inner ends with relatively rigid support brace portions extending into and bearing against the walls of said indentations to thereby anchor and position the said inner ends of the conductors in place within the envelope and accurately locate and maintain the said translation element in predetermined optical position relative to the reflecting surface of the reflector section.

3. An electric lamp or similar device comprising a sealed envelope including a glass reflector section and a glass cover section joined together at their rims by a fused seal, fllarnent means within said envelope, and a plurality of lead-in conductors sealed through the fused seal and connected to the said filament means, said reflector section having its inner surface formed with locating indentations corresponding in number to said conductors, and said conductors being provided adjacent their inner ends with support brace portions extending into and bearing against the walls of respective ones of said indentations to thereby anchor and position the said inner ends of the conductors in place within the envelope and accurately locate and maintain the said filament means in predetermined optical position relative to the reflecting surface of the reflector section.

4. An electric lamp or similar device comprising a sealed envelope including a glass reflector section and a glass cover section joined together at their rims by a fused seal, an electrical enorgy translation element within said envelope, and a pair of relatively rigid lead-in conductors sealed through the said fused seal and connected to the said translation element, said reflector section having its inner surface formed with a pair of locating indentations therein, and the inner ends of said lead-in conductors extending into and bearing against the walls of respective ones of said indentations to thereby anchor and position the inner end portions of said conductors in place within the envelope and accurately locate and maintain the said filament means in predetermined optical position relative to the reflecting surface of the reflector section.

5. An electric lamp comprising a sealed envelope including a concave glass reflector section and a glass cover section joined together at their rims by a fused seal, a filament mounted within said envelope in predetermined optical position relative to the reflecting surface of said reflector section, and a pair of lead-in conductors sealed through the said fused seal and extending inwardly therefrom toward the axis of said reflector section and connected to the said filament, said reflector section having its inner surface formed with a pair of locating indentations disposed adjacent the reflector axis, and said conductors being provided with rigid support brace portions extending in the general direction of the reflector axis into respective ones of said indentations and bearing against the walls thereof to thereby anchor the inner end portions of said conductors and position and maintain the filament in said predetermined optical position.

5. An electric lamp comprising a sealed envelope including a concave glass reflector section and a glass cover section joined together at their rims by a fused seal, a filament mounted within said envelope in predetermined optical position relative to the reflecting surface of said reflector section, a pair of lead-in conductors sealed through the said fused seal at diametrically opposite points thereof and extending inwardly therefrom toward the axis of said reflector section and connected to the said filament, said reflector section having its inner surface formed with a pair of locating indentations disposed on opposite sides of and adjacent the reflector axis and said conductors being provided with rigid support brace portions extending in the general direction of the reflector axis into respective ones of said indentations and bearing against the walls thereof to thereby anchor the inner end portions of said conductors and position and maintain the filament in said predetermined optical position, and an insulative bridge member fastened across the said support brace portions of the conductors and tying them together.

LEONARD F. KRAMEL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,114,350 Lee Apr. 19, 1938 2,543,093 Braunsdorff Feb. 2'7, 1951 

